Considering where this EO came from, I have a feeling the INTENT is directed at the 80% receiver. However, there's specific wording:
"For the purpose of this subchapter, engaging in such a business requires only one occasion of
manufacturing..."
Basically, this wouldn't change anything for a private citizen who doesn't sell, or intends to sell, their "manufactured" part.
Getting back to the 80% however, this is my concern:
"Use of any special tooling or equipment upgrading in order to improve the capability of assembled or repaired firearms;"
So, an 80% is NOT a firearm, that's not in argument. However, can the 80% be used to improve an existing firearm? Say for arguments sake, an AR clone?
Rational AR owners would say "Of course not" since it doesn't need an 80% to function. The argument I believe may come up however, is that the 80% can be made into a "M" receiver.
In any event, the current Executive Office has made it clear that U.S. Laws aren't relevant, with this (not to mention agreeing with ITAR at all) and the superceding of DOMESTIC shipping requirements with INTERNATIONAL requirements, to the point where I have to wonder why the current Executive Office still exists.